1. Field of the Invention
This invention relates to an apparatus for and a method of blocking a vein branch.
2. Description of the Related Art
Recently, a surgical operation has been performed for bypassing, by means of a saphena, a blocked artery which causes stasis of blood stream due to thrombus or atheroma in a leg. Since a part of a vein is used as a part of a damaged artery in this surgical operation, it is necessary to cut the venous valve of the vein. In doing so, openings are formed at the upstream and downstream portions of the vein to be cut, and the vein is clamped at the vicinity of those openings to be blocked. Thereafter, a cutting apparatus is inserted from the upstream opening in the vein so as to be placed at its required position and then pulled to cut the vein. As a vein has a lot of vein branches, it is necessary to block them at the vicinity of the vein by means of a blocking apparatus.
Japanese Laid-open Patent Application No. 64-2639 discloses a clipping apparatus, as an example of a vein-branch blocking apparatus, for blocking a vein branch externally by surgically cutting a living body in order to prevent blood from flowing in the vein branch. With this clipping apparatus, a scissor-like clip is pushed out from the vein by means of a push-out member so that the vessel is flattened to be blocked. Alternatively, the vessel is blocked by a thread or the like.
In the conventional surgical operation for bypassing a membrum inferius as described above, the related portion is cut along the vein portion used as a bypass of an damaged artery and then the vein branches are externally blocked by clips, threads or the like. This method is encountered with the problem that the surgically operated patient must stay in a hospital for a long time until he or she is cured from disease because the related portion is cut by a long length along the vein portion to be used for bypassing the artery.
The conventional surgical operation method is also met by a problem that it is difficult to cut the required portion accurately because it needs the step for checking the positions of the vein branches by the use of a vein cutting apparatus disposed in the vein portion. In addition, this method requires a long time.